Re: Float numbers equality.

2013/8/13 KHMan <keinhong@gmail.com>

I don't see any comparison anywhere... Where does the equality comparison fit in?

Here is the code, extracted and simplified from my test case.

This is the case when measuring apparatus gives a normalized value.

-- input vales

O2 = 12.95

H2O = 100 - (100 / 1.2)

T = 136.575

P = 1013.25 / 1.25

O2_r = 10.95

H2O_r = 0

T_r = 273.15

P_r = 1013.25

SO2_in = 5.3333333333333

-- calculations

-- correction factor

O2_cf = (20.95 - O2_r) / (20.95 - O2)

H2O_cf = (100 - H2O_r) / (100 - H2O)

T_cf = (T + T_r) / T_r

P_cf = P_r / P

print (

O2_cf, O2_cf == 1.25,

H2O_cf, H2O_cf == 1.2,

T_cf, T_cf == 1.5,

P_cf, P_cf == 1.25

)

-- normalized value

SO2 = SO2_in * (O2_cf * H2O_cf * T_cf * P_cf)

print (

SO2, SO2_in * (O2_cf * H2O_cf * T_cf * P_cf),

SO2 == SO2_in * (O2_cf * H2O_cf * T_cf * P_cf)

)

-- inverse operation: from normalized value calculating measured value

-- !!!

print (

SO2_in, 15 / (1.25 * 1.2 * 1.5 * 1.25),

SO2_in == 15 / (1.25 * 1.2 * 1.5 * 1.25)

)

assert (SO2_in == 15 / (1.25 * 1.2 * 1.5 * 1.25))

2013/8/13 KHMan <keinhong@gmail.com>

So, assuming you now know about floating point, do you still require an equality comparison?

Yes, I think this is the best way to test.